Welding apparatus control



March 27, 1934. G. G. LANDlS 1,952,505

WELDING APPARATUS CONTROL Filed May 17, 1952 TIME DELAY SWITCH TIMEDELAY swn'cu INVENTOR.

55 Z G fiorye G Land/o BY M 1 $44 ATTORNEYS Patented Mar. 27, 1934 l1,952,505

UNITED STATES PATENT OFFICE WELDING APPARATUS CONTROL George G. Landis,Cleveland, Ohio, assignor to The Lincoln Electric Company, Cleveland,Ohio, a corporation of Ohio Application May 17, 1932, Serial No. 611,805

8 Claims." (l. 219-8) This invention relates, as indicated, to weldingof a control system modification of that illustratapparatus control andhas 'more particular refed in Fig. 1. .erence to the control of thewelding current gen- Referring now more specifically to the drawing,erating plant so that the operation thereof may the welding currentgenerating plant comprises a I very closely correspond to therequirements of generator 1 of the usual type, which is driven by 60 thewelding arc. some power means such as an electric motor 2.

As is well known, the plant for generating the- As hereinafter morefully explained, the princiwelding current usually comprises a generatorples comprising this invention are equally apwhich is driven by somemotive power, such as plicable to a generating plant in which the motivean electric motor, or an internal combustion enpower is furnished by anywell-known means, 65

gine where no electric power for driving the plant such as an internalcombustion engine and the is available. In order to conserve the energylike. which would be normally dissipated by internal The welding currentgenerator 1 has leads 3 resistance in the apparatus when running idle,and 4 associated therewith which are respectively ii and also to reducethe wear on such apparatus, connected to the work and a weldingelectrode 70 the generating plant' for the welding current generallyindicated at 5 adapted to be presented should be running only during thetime during in arcing relation to the work. Of course, a suitwhich thewelding operation is inactual progress, able holder will be provided forsupporting and i. e., during the time while the are is maintained.manipulating the electrode 5 and it is immaterial,

To immediately shut down the welding current so far as concerns thepresent invention, whether 76 generating plant each time the welding arcis 'such electrode be of fusible orv non-fusible type. ruptured isusually impractical and undesirable The electrode holder, regardless ofits particular for a number of reasons. In a number ofinform, will beadapted, either by the employment stances, the welding arc istemporarily ruptured of a hook 6 'or similar means, to be hung on asupsimply to enable the operator to-make minor-adport 7 by the operatorwhen the welding opera- 80 justments in the work or to replace or adjustthe tion is to be interrupted for any appreciable welding pencil. Duringsuch short periods it is period. desirable that the generating plantcontinue to The motor 2 which drives the generator has operate atsubstantially full speed. If, however, leads 8 and 9 associatedtherewith which connect the period of interruption is long enough sothat such motor to the incoming power line. The rep- 86 an operatorwould ordinarily lay aside the elecresentation of the field and armaturewindings of trode holder, at least for the time being, the genbothmachines has been omitted for the reason Grating Plant can be pp at eastreduced that it is unnecessary to include a showing of the to i in speedto be again r h p to p r same to the, full understanding of thisinvention. Sp e when he W lding operation is to re- The power circuitforthe motor'2 contains a sume. switch, generally indicated at 10, which,when It is among the j s of h invention to such switch is opened orclosed, will de-energize P a Control System fo W d u e t g orenergizethe motor. The switch 10 is normally Grat app which S a l fuction n the maintained in its closed position by some means '40 aboveindicated desirable manner. 7 such as a spring 11 and is adapted to beopened --T th accomplishment of th foregoing and by the energization ofa solenoid, the armature 12 related ends, said invention, then, consistsof the of which is diagrammatically illustrated in the means hereinafterfully described and particudrawing as connected to the wit h 10,

larly pointed out in the claims; the annexed The winding 13 of theswitch-operating sole- 45 drawing and the following desc iption Settingnoid is in series with a suitable source of supply,

forth in detail certain means of carrying out the such as a battery 14,and also in series with a invention, such disclosed means illustrating,howtime-delay switch, generally indicated at 15. The ever, but one ofvarious ways in which the printime-delay switch at 15 may be of anywell-known ciple of the invention may be used. type, such as a dashpot,a mercury switch, etc.

50 In said annexed drawing: Such time-delay switch is, however, actuatedby Fig. 1 is a diagrammatic representation of the the lever '7 on whichthe electrode holder is hung several elements of the welding currentgenerat by the operator. The arrangement of the parts ing plant showingin association therewith ne is suchthat when the electrode holder is notform of the control system comprising'this invenhung on the hook 7 thetime-delay switch 15 55 tion, and Fig. 2 is a diagrammaticrepresentation maintains the circuit, including the solenoid 13,

l l l open so that the spring 11 may close the switch 10 and completethe power circuit to the motor 2. The time-delay switch 15 will alsopreferably be adjustable in its nature so that the period from the timethe electrode holder is hung on the hook 7 to the time when such switchcloses the circuit of the solenoid coil 13 may be varied to suitparticular operating conditions.

The operation of the above described control system is briefly asfollows: The hook 7 will be so positioned that the operator will hangthe electrode holder thereon during all normal'interruptions of thewelding operation. This will trip the time-delay switch 15. If theelectrode holder was hung on the hook 7 simply to effect a minoradjustment either of the electrode or the work, and is taken down fromthe hook within a relatively short time, the switch 15 will not have hadan opportunity to close the circuit of the solenoid coil 13 and hence,the motor 2 continues to operate at full speed. Should the holder beallowed to remain on the hook 7 for a time greater than thepredetermined setting of the switch 15, the circuit of the solenoid coil13 will eventually be closed and the armature 12 drawn upwardly, openingthe switch 10, thereby permitting the driving motor to come to rest. Assoon as the electrode holder is removed from the hook 7 the solenoidcoil 13 is de-energized, permitting the spring 11 to close the switch10, whereupon the motor 2 is immediately energized and the generator 1brought up to the proper speed preparatory to the establishment of theare between the electrode and the work.

The system illustrated in and described in connection with Fig. 1, itwill be noted, stops the welding current generating mechanism at the endof a predetermined time interval after the electrode is hung onto itssupporting hook. Instead of stopping the welding current systemcompletely each time the electrode remains on the hook for apredetermined length of time it may be desirable to simply reduce thespeed of operation of such apparatus or otherwise vary its operatingcharacteristics so that the energy consumption of the apparatus whilerunning idle is reduced to a minimum. One manner in whichthe idlingoperating characteristics of the apparatus may be varied so as toconserve energy during the idling period is illustrated in Fig. 2- inwhich the generator and motor respectively 1 and 2 have associatedtherewith an exciter 16 which is driven from the motor either directlyor indirectlyand which supplies the current to the exciting winding 17of the generator. In the system illustrated in Fig. 2 instead of openingthe supply line to the motor 2 and thereby stopping the apparatus Ipropose to reduce the apparatus to idling speed and otherwise reduce thecurrent consumption when idlinguat the expiration of a predeterminedtime interval after the electrode is placed on the hook 7. r

The specific apparatus chosen for purposes or illustration, shown inFig. 2, for accomplishing this result comprises variable resistances l8and 19 in the circuit of the motor and exciter. The value of theseresistances in series in their respective circuits may be varied bymeans of contact members 20 and 21 adapted to be simultaneously actuatedby the movement of some such means as a rack 22 associated with thearmature 12a of the solenoid winding 13a. The armature is normallymaintained in the position illustrated in Fig. 2 by means of a spring 23and is forced to the right against the influence of such spring when thecoil 13a is energized. The travel of the armature 12a to the right, andaccordingly'the arcuate movement of the contact arms 20 and 21 may becontrolled by an adjustable stop 24 which may be in the form of athreaded screw carried in a suitable support and adapted to engage theend of the rack 22.

When the form of control system such as is illustrated in Fig. 2 isemployed, the placing of the electrode on the hook 7 for a time intervalsuch as to permit the time-delay switch to close the circuit includingthe solenoid coil 13a and thereby energizing such solenoid moves therack 22 to the right inserting the resistances 18 and 19 in series withthe motor 2 and the exciter winding 17 of the generator 1. The motor isaccordingly slowed down, the exciter field of the generator reduced to aminimum and hence the power consumption reduced to a very minimumwithout actually bringing such apparatus to rest.

It should be noted that it is within the contemplation of my inventionto provide means (or individually actuating the contact, members 20 and21 andapparatus materially different from that shown in the drawing forpurposes 01' illustration may be employed to .accomplish thehereinbefore set forth results.

As above indicated, it is within the contemplation of this invention toemploy any other suitable means, such as an internal combustion engine,for driving the generator 1, and when such means is employed thesolenoid armature 12 will be connected to the throttle lever for suchengine so that the control effected by the system comprising thisinvention will be substantially as above described.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means 118 stated by any of the followingclaims or the equivalent of such stated means be employed.

I, therefore, particularly point out and distinctly claim as myinvention:

1. In electric arc welding apparatus, the com bination of a weldingcurrent generator, driving means for such generator, means forsupporting the welding electrode holder when the same is not in use, andmeans for varying the operating characteristics of said driving means atthe expiration of a predetermined time interval after such weldingelectrode holder is placed on said supporting means.

2, The combination with electric arc-welding apparatus including agenerator and an electric motor for driving the same, an externalresistance adapted for connection in series with the power line to saidmotor, means including a time delay switch efiective at the expirationof a predetermined time interval after actuation, for so connecting saidresistance in series with said motor, and means for supporting theelectrode when not in use adapted when the electrode is placed thereonto actuate said time delay switch.

3. The combination with electric arc-welding apparatus including awelding current generator and exciter means for such generator, of meansincluding a time delay switch effective at the expiration of apredetermined time interval after actuation to reduce the excitation ofsaid generator, and means for supporting the electrode when not inuseadapted when the electrode is placed thereon to actuate said time delayswitch.

4. The combinationwith electric arc-welding apparatus including awelding current generator,

driving means for such generator and exciter means for such generator,of means including a time delay switch effective at the expiration of apredetermined time interval after actuation to reduce the speed of saiddriving means and to reduce the excitation of said generator, and meansfor supporting the electrode when not in use adapted when the electrodeis placed thereon to actuate said time delay switch.

5. The combination with electric arc welding apparatus including awelding current generator, of control means including a time delayswitch under control of the operator at the welding station andcontrolling a circuit independent of the welding circuit effective atthe expiration of a predetermined time interval after actuation to varythe operatingcharacteristics of the generator.

6."I'he combination with electric arc welding apparatus including awelding current generator and driving means for such generator, ofcontrol means including a time delay switch under control of theoperator at the welding station and controlling a circuit independent ofthe welding circuit, effective at the expiration of a predetermined timeinterval after actuation to vary the operating characteristics of saiddriving means.

'7. The combination with electric arc welding apparatus including awelding current generator, of control means including a time delayswitch adapted for actuation by a motion of the operator other than abreaking of the arc, said control means effective at the expiration of apredetermined time interval after actuation of said switch to vary theoperating characteristics of said generator.

8. The combination with electric arc welding apparatus including awelding current generator and driving means therefor, of control meansincluding a time delay switch adapted for actuation by a motion of theoperator other than a breaking of the arc, said control means effectiveat the expiration of a predetermined time interval aften. actuation ofsaid switch to vary the operating characteristics of said driving means.

GEORGE G. LANDIS.

